Production of granular substances



Aug. 19, 1930. Q H, SUSE 1,773,257

PRODUCTION OF GRANULAR SUBSTANOES Filedy Feb. 15. 1928 lar su y but in this case the width of the buildingi Patented Aug. 19, 1930 UNITED STATES PATENT oFFlcE OTTO H. BUSE, OF CLEVELAND, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS TO THE GRASSELLI CHEMICAL COMPANY, OF CLEVELAND, OHIO, A CORPORATION OIEy DELA- WARE PRODUCTION OF GRANULAR SUBSTANCES l Application led February 13, 1928. Serial No. 254,089.

The present invention relates to a method and apparatus for the production of granustances.

It is advantageous to be able to readily produce numerous materials, particularly chemical roducts, in the granular or globu-l lar form, ecause of the convenience oi' handlin and the freedom from dusting of materia s in that form. These and other advantages have led to a constantly increaslng 'demand for the production of chemical products in granular form.

Those substances which are produced in the molten state or which may be melted readily without deterioration may be granulated by allowing drops of the molten material to fall throu h the air. This, of course, may be done gy the use of towers such as are used in the production of lead shot. But to produce globular material of a desirable size, e. g., 1 to2 mm. in diameter, ,inconveniently high towers would frequently be required.

f Theheight of the structure can be\ decreased b spraying the material upward, thus doub ing the trajectory of the droplets,

must be considerably increased. If the droplets strike any hard surface, such as the walls,

ceiling or ioor of the buildin before complete solidiiication, they wil agglomerate into s'olid masses or larger chunks which are, of course, undesirable in the production of line granules.

In the granulating or olobularizin of materials, such as sodlum bisulfate, w ich are corrosive in their molten state, it is particularly impractical to erect structures of large dimensions, as supporting members have to be omitted from t e interior.

I have found that small buildin scan be used for this purpose if the wal s of the building are blanketed by a swiftly moving current of air'or an inert gas. 'This prevents the droplets from hitting the walls before they are'solidiied and has the added advantage of carrying away the heat of crystallization and keeping the center air space cool, which in turn produces a quicker solidification.

It is obvious that this `principle couldlbe the Figr2 is a section on the line 2-2 of Fig. 1.

The cooling space 1 is delimited by the walls 2 and rooi:I 3 of the structure. The molten sodium bisulfate is forced from the egg or lblow case 4 through pipe 5 to spray nozzles 6. ,Fans 7 located approximately at the lower corners of the structure, and directed approximately tangential to the periphery of the interior space, createa peripheral air current about the lower walls of the space. Blowers 8 situated centrally in the u per part of the side walls, together with efiecting plates 9, produce an upward current of air which blankets the upper part of the walls and the ceiling of the structure and passes out through medially located roof vents 10.

Air from the lower peripheral current also ultimatelyfror'ms apart of this upward .cur-l It will be obvious' that the walls and ceiling of the coolingspace are protected from contact with uncooledlparticles by cans of blanketing air currents which eec'tively preor aglomeration of such uncooled particles. In ot er words, particles which enter these blanketing currents havegtheir path so increased in the direction of the current that do not come into Contact with the walls an ceiling of the structure until the particles have been sufficiently cooled that they will not coalesce.

^ It will also be obvious that the particular arrangement and number of fans or blowers, or other means of creating the desired air currents, may be varied according to the size and shape of the structure in which the ranulation iscarried out and according to t e charvent any substantial amount of incrustation acteristics of the material to be granulated.

This invention will be seen to comprise the granulation of substances solid at ordinary temperatures by sprayin the substances in the liquid or semi-liqui condition into a cooling space enclosed within peripheral air currents, and structures adapted lto carrying such a process into effect.

I claim:

1. A method of granulating substances, solid at ordinary tem eratures, which comprises s'praying the su stances in the liquid condition into a space containing a body of relatively stagnant air substantially surrounded by swiftly moving air currents.y

2. A method of granulating sodium bisulfate which comprises spraying the sodium bi sulfate in the molten condition into a space containing a body of relatively stagnant air substantially surrounded by swiftly moving air currents.

3. A method of granulating substances,

' ly surrounded by swift -y air currents.

4. A method of granulatin sodium bisulfate which comprises upward y spraying the sodium bisulfate in the molten condition into a space containing a body of relatively sta nant air substantially surrounded by swiftly moving air currents.

5. Apparatus for the granulation of substances, `solid at ordinary temperatures, comprising a cooling space, means for spraying the substance in the liquid condition into said space, and means for producing swiftly movin air currents substantially parallel and adjacent to the walls forming the outer boundaries of said space.

6. Apparatus for the granulation of substances, solid at ordinary temperatures, comi prising a cooling space, means for spraying` the substance in the liquid condition into said j space at about its center, and means for producing swiftly moving air currents substantially parallel and adjacent to the walls form-f ing the outer boundaries of said space.

7. Apparatus for the granulation of substances, solid at ordinary temperatures, comprising a cooling space, means for upwardly spraying the substance rin the liquid condition into said space at about its center,`and means for producing swiftly moving air currents substantially parallel and adjacent to the walls forming theA outer boundaries of said space.

8. Apparatus for the granulation of` sodium bisulfate comprising a cooling ace sP i means for sprayingthe sodium bisulfate in the molten condition into said space and means for producing swiftl movin air currents substantially paralle and a )acent to the walls forming the outer boundaries of said s ace.

9. pparatus for the granulation of sodium bisulfate com rising a coolin space, means for spraying t e sodium bisul ate in the molten condition into said space at about its lim 

